US2842210A - Hydraulic motor operated formation tester - Google Patents

Description

HYDRAULIC MOTOR OPERATED FORMATION TESTER Filed Jan. 29. 1954 G. H. RAMSEY July s, 1958 2 Shee ts-Sheet 1 F l G.

George H. Ramsey INVENTOR ATTORNEY July s, 1958 G. H. RAMSEY 2,842,210

' RMATION TESTER G e o r g e H R a m s e y N v E N T OR Unit HYDRAULIC MOTOR OPERATED FORMATION TESTER Application January 29, 1954, Serial No. 407,119

3 Claims. (Cl. 166-100) This invention concerns a novel form of formation tester for use in testing the fluids which may be produced at a given point along a Well bore. The apparatus of this invention is of application in the exploration for oil and is. uniquely designed to provide simple and efficient means for sampling fluids produced in a bore hole at a given horizon or stratum ofthe earth.

In drilling a bore hole in the attempt to encounter oil deposits in the earth, it is conventional practice to employ a variety of tests to determine whether or not oil may be produced from the bore hole, todetermine the nature of the oil, it any, and to determine from which stratum or strata production should be attempted. The type of apparatus used to provide this type of information is generally called formation testing apparatus. This term aptly identifies the principal objective of the apparatus: .to test the fluids existing at a particular stratum of the earth. For this purposea wide variety of formation testers are known. A particularly attractive development of rather recent date has been the development of inflatable packer type formation testers. Testers of this type have an elastic packer whichmay be inflated by fluid. pressures. so as to completely seal oflf a particular portion of a bore hole. In one of its most desirable embodiments, a portion of the inflatable packer is provided with a permeable membrane, or alternative means, through which fluids maypass from strata ad- .jacent the sealed off section of the borehole into channels and chambers provided in the apparatus to receive the sampled fluids. This type of packer provides a convenient and effective manner of sealing off the drilling mud inthe bore hole so that. a sample of Well fluids can be obtained from any desired stratum of the bore hole.

One of the problems involved in obtaining fluid samples from a formation tester of this character is provision of a. suitable means for extractingfluid from the producing stratum. For example, it isoften unsatisfactory to rely upon use of a vacuum pump at the surfaceof the earth to produce fluid from a stratum. The limitation inherent in use of a vacuum pump is that an effective head of only about thirty feet of water may be applied on the producing stratum by this means. It

has been suggested to use a sample chamber which will be essentially evacuated when placed in fluid communication with the stratum to be sampled. In this case evacuation of a sample of fluid from the formation will be effectively. obtained; but itis apparent that the fluid capacity of the sample chamberis seriously limited. Consequently, it is one of the objects of this invention toprovide formation testing apparatus in which it is possible to obtain fluid flow from the formation to be tested into a substantially empty drill .pipe. This technique provides an ample pressure differential which is applied at the producing stratum so as to ensure production and recovery of any fluid which maybe present. Again, there is suflicient volume within the drill string (extending as it does to the surface of the earth) so that any ordinarily required volume of .fluid. sample may be withdrawn.

2,8412 10 Patented July. 8, 1958 Another problem connected with the use of inflatable packer type formation testers is provision of a suitable means. for inflating these packers. This problem becomes particularly diflicult to solve when provision is made, as indicated, for use of an empty drill. string into which the produced fluid is to flow. In this case it is apparent that drilling mud cannot be circulated downwardly through the drill string to inflate the packer and that other means are required. It is one of the features of this invention, therefore, to employ a hydraulic motor driven by the hydrostatic. pressure .of drilling mud .in the annulus of the bore hole about the drill string. This hydraulic motor may be directly coupled to a mudv pump which can be used toforce drilling .mud from the annulus of the bore hole'to inflate the packer. A particular advantage of this arrangement is the simple and effective operation made possible by effectivelyutilizing the pressure differential between drilling mud in the annulus .of the bore hole and the empty drill string.

The formation tester of this invention, having the characteristics generally indicated, may conveniently be designed to permit positive sequential operatingsteps. Thus, in a first step, inflation of the packer of the formation testeris achieved'by operation-of the hydraulic motor-mud pump combination. In a second step of the procedure the hydraulic motor and mud pump can be stopped and fluid can be produced through the inflated packer into the drill string. Finally, in a third step of the process the packer'can be deflated so that theentire apparatus can be removed from thebore hole, thereby bringing to the surface; the produced 'fluid contained 'within the drill string. It is one of the features of this invention to provide a sequential step-type valve operation to carry out these essential steps in formation testing.-

In' orderto fully illustrate the principles ofthis invention, reference will bemade to the accompanying drawings, in which the preferred form ofthe invention is schematically illustrated. In these drawings:

Figure 1 is a cross-sectional, elevational detail of'the formation tester illustrated in operative position as it would be in a bore hole;

Figures 2, 3, 4, and 5 are cross-sectional views of Figure 1 along the line IL-II illustrating the valve connections, and sequential valve positions;

Figure 6 is afragmental, diagrammatic sketch of the valve operating latch;

Figure 7 illustrates a solenoid arrangement for actuating the valve-operating ratchet mechanism of Figure 1; and

Figure 8 is a cross-sectioned schematic detailed view of valve 18 shown in Figure 1.

Referring to the drawings, the formation tester may be connected to a drill string 2 inorder to suspend the tester at any desired level in a bore hole. The uppermost portion of the tester constitutes a valve 3 operating within a valve body element 4 in which fluid' channels leading to the valve are positioned. As illustrated, the valve body 4 may be connected to the drill string 2 inthreaded relation. The valve 3' may constitute a plug valve held in the the, valve body by means of the cover plate 5. In order to permit sequential positioning of the valve, a torsion spring 6 is positioned about the valve stem so that in an initial step of the operation the valve can effectively be Wound up against the force of the spring 6. A ratchet 7 which may be suitably fixed to a support 8 carried by valve body 4 can be used to contact teeth out on the upper portion of the valve. As will bedescribed, the teeth are so.formed that each time the ratchet 7 is momentarily released the valve will turn one quarter of a revolution.

In this manner the valve may be turned sequentially into any one of four positions so as to connect diflerent valve ports to the interior of the drill pipe above the valve body 4.

Any suitable means may be used to operate the ratchet 7 in order to turn the valve as desired. For example, a wire line 60 may be connected to the ratchet 7 so that the valve can be turned each quarter turn when desired. Again, for example, the ratchet may be controlled by a solenoid 61 supported by arm 62 from support 8 as shown in Figure 7 so as to control the different sequential valve positions. The solenoid may be operated remotely from the surface of the earth through suitable leads 63.

Suspended below the valve body 4 is a cylinder 9 within which is supported a centrifugal pump 10 and a hydraulic motor 11 which are diagrammatically illustrated by the rectangles in the drawing. Drilling mud maintained in the annulus of the bore hole has direct fluid communication with the inlet of the hydraulic motor through the port 12. The outlet of the hydraulic motor is connected to a conduit 13 which extends upwardly so as to connect with fluid channel 14 in the valve body 4. The hydraulic motor 11 may be directly coupled to the centrifugal pump 10 through a shaft 15. The inlet of pump 10 is normally in fluid connection with drilling mud in the annulus of the bore hole through port 17. As will be described, a. valve 18 may be used to close the port 17 when it is desired to discontinue operation of the centrifugal pump. The outlet of the centrifugal pump is connected to a conduit 19 which leads to a second fluid channel 20 in the valve body 4.

The cylinder 9 carrying the centrifugal pump and fluid motor may be fixed to the valve body 4 in any desired manner. For example, as shown, the cylinder 9 may be force-fitted over a reduced cross sectional portion of valve body 4. An O-ring seal 23 or the like may be employed to ensure a fluid seal. Set screws 24 may be used to lock these elements in position. If desired, keys 25 may extend along the cylinder 9 through the casing of the centrifugal pump and the casing of the hydraulic motor so as to maintain these elements in the proper rotational register. j

Suspended from the bottom of the cylinder 9 is a suitable form of inflatable formation tester packer identified by number 30. As will be understood this invention may be employed with a wide variety of inflatable packers. For example, one form of packer which may be used is that described in U. S. Patent No. 2,600,173, issued to Ben W. Sewell and George H. Ramsey on June l0, 1952. This packer is fragmentally illustrated in the lower portion of Figure l of these drawings. A shown, the inflatable packer may be connected to cylinder 9 by means of a wirewrap 31. The necessary fluid connections to the packer may be made through a closure element 32 extending across the lower termination of the cylinder 9. One channel, indicated by numeral 33, may be cut through the closure element 32 so as to provide fluid access directly to the interior of the packer so that fluid can be forced therethrough, for inflation of the packer. Channel 33 is connected to a conduit 34 which in turn leads to a channel 35 cut in the valve body 4.

A second fluid connection to the formation tester packer 30 is made through the channel 37 which is connected to a formation fluid sampling passage or tube 38 through which fluid produced during a formation test may flow. A conduit'39 leads upwardly from the channel 37 for connection with a channel 40 in the valve body 4. The lower end of tube 38 extends through the wall 70 of the packer and connects with a packet 71 which is filled with a filling material as more fully described in the aforementioned Sewell et al. patent. l

Since the elements of the formation tester packer 30 are not a portion of this invention, no further description will be made of the formation tester. As indicated, it is only necessary to provide a fluid conduit such as conduit 34 through which drilling mud can be introduced to inflate the formation tester and also to provide a conduit 39 which can be connected to the portion of the formation tester through which produced fluid can flow.

The operation of the apparatus described can be understood by reference to Figures 2, 3, 4, and 5, which illustrate the fluid passages which are opened at different rotational positions of the valve 3. When the apparatus is to be lowered into a bore hole in order to carry out a formation test, the valve opening 45 will be in a first position illustrated in Figure 2. In this position, the valve will be closed so that fluid can neither flow into nor out of the drill string 2. Consequently, the packer of the formation tester will remain deflated and neither the hydraulic motor nor the centrifugal pump will be in operation.

When the formation tester has been lowered to the position in the bore hole at which it is desirel to conduct a formation test, ratchet 7 is triggered so as to permit a quarter turn of the valve 3. The valve will then be in the position particularly illustrated in Figure 3. In this position, the outlet of the motor, connected to conduit 13 and valve port 14 will be in fluid communication with the interior of the drill string 2. Consequently, drilling mud can flow from the annulus of the bore hole through port 12 so as to operate the hydraulic motor. The drilling mud will be exhausted from the motor through conduit 13, fluid channel 14, valve port 45, and thence into the drill string above the valve body 4. Operation of the hydraulic motor in this manner will simultaneously activate the direct coupled centrifugal pump 10. This will cause drilling mud to be forced by thepump from the annulus of the bore hole through inlet 17 and through v conduit 19 to the valve body. In this step of the operation a cutaway 46 in the valve body serves to connect channels 20 and 35 in the valve body so that the drilling mud pumped through conduit 19 will be forced through conduit 34. Thereby operation of the centrifugal pump 10 serves to force drilling mud into the inflatable packer 30 so as to inflate this packer. The centrifugal pump may be so designed as to deliver suflicient pumping pressure to suitably inflate the packer without exceeding the rupture limits of the packer. Alternatively, the arrangement illustrated in Figure 1 may be used to stop operation of the pump when a suitable inflation pressure has been obtained. Thus, as illustrated, a conduit 48 may be connected to conduit 34 so as to lead to the valve arrangement 18. The valve 18 may be controlled by a spring biased piston so that when a selected pressure has built up in the packer 30, valve 18 will be closed. It may be noted that operation of this valve is simple and positive as the hydrostatic pressure within packer 30 will sharply build up when inflation has been completed.

A sectioned schematic view of a simple valve 18 is shown in Figure 8. The valve illustrated there includes a piston attached to the valve stem which is biased against fluid pressure within conduit 48 by virtue of the spring 81.

In the next step of the operation, ratchet 7 is again triggered so as to permit the valve 3 to make another quarter turn. In this position of the valve illustrated in Figure 4, the valve port 45 will be connected with channel 40 in the valve body so that conduit 39 leading to the formation tester will be in direct fluid communication with the drill pipe. This position of the valve will serve to cut 05 flow of drilling mud through the hydraulic motor so that the motor and pump will be stopped in this step of the operation. Since the drill pipe will be completely devoid of fluid except for the drilling mud which as passed to it by operation of the motor, there will be opportunity for fluid at very low formation pressures to flow into the drill pipe. The apparatus may be maintained to permit this flow for any desired period of time so that a substantial quantity of fluid sample can be obtained in the drill pipe.

In the next step of the operation ratchet 7 is triggered so that the valve port 45 will be brought in register with channel 35 connecting to the interior of the inflatable packer as shown in Figure 5. Thereby the packer may exhaust into the drill string so as to deflate the packer. Regardless of the quantity of the fluid which has been sampled and trapped in the drill string, the hydrostatic pressure of the drilling mud in the bore hole acting on the packer will be sufiicient to fully deflate the packer during this step of the operation.

Finally, as the last step of the procedure the valve may again be rotated a quarter turn to the position shown in Figure 2 so that valve port 45 is no longer in fluid communication with any conduits of the apparatus. Consequently all fluid which has entered the drill string will remain trapped until the apparatus is brought to the surface of the earth and this fluid can be removed.

It is apparent that the invention described is subject to many refinements and modifications. As indicated, the apparatus is illustrated diagrammatically, so that in actual construction it would not be necessary to employ the different conduits referred to. The centrifugal pump, the hydraulic motor, and the valve body, for example, can all be constructed in an integral assembly provided with suitable channels to carry out the fluid flow described. Again, it must be appreciated that this invention can be used with any desired type of formation tester other than the formation tester particularly-described.

Illustrated in Figure 6 is one modification permitting substitution of a weight activated valve latch in place of the wire line operated valve latch described. In Figure 6, for clarity, the teeth 51, 52, 53, and 54 at the upper portion of the rotary valve are illustrated in linear position. The latch 7 is positioned above the teeth and is pivoted at point 55. On each side of the pivot point, two extensions 56 and 57 extend downwardly in order to contact the teeth 51 to 54. Extension 56 is somewhat longer than extension 57 and the distance between extensions 56 and 57 is less than the distance between each of the teeth 51 to 54. The latch 7 may be constructed so that the anvil 50 is at the center of the bore hole. A torque spring about the pivot of the latch may be used so that extension 56 is normally urged against the teeth 51 to 54. Consequently when a wire line suspended weight is dropped on anvil 50, extension 56 will be lifted free of the valve teeth while extension 57 is brought downwardly enough to contact these teeth. In particular, valve tooth 52 would bereleased, as illustrated, and extension 57 would contact tooth 53. This prevents possibility for the valve turning more than one quarter turn.

When the wire line weight is then removed from the anvil, extension 56 will contact tooth 53 as the valve turns, to establish the desired 90 rotation of the valve.

What is claimed is:

1. In a well formation tester including an inflatable elastic packer and a sample conduit extending through the wall thereof, the improvement which comprises a cylinder attachable at its upper end to the lower end of a string of well pipe and at its lower end to said packer, a hydraulic motor and a pump in coupled relation mounted within said cylinder, a four-position valve mounted within said cylinder above said motor and pump and separating the interior of the well pipe from the interior of the packer, said valve having a shut-position and three sequential port positions, the movable part of the valve being rotatable within the valve body and having a passageway communicating at one end with the interior of the well pipe, three separate ports in the body of said valve, the opposite end of said passageway being blocked by said valve body in a first said shut-position and registering sequentially with a first, second, and third of said three ports in the following three port-positions, the intakes of said motor and said pump extending exteriorly of said cylinder, a first conduit connecting the exhaust of said motor with said first port, a second conduit connecting said second port with the end of said sample conduit within said packer, a third conduit connecting said third port and the interior of said packer, an additional port in said valve, a fourth conduit connecting said additional port and the exhaust of said pump, and a bypass passageway within said movable part operable to communicate between said additional port and said third port when the valve is in its first port position.

2. A well formation tester which comprises: a cylinder having a closure at its lower end and attachable at its upper end to a string of well pipe; an inflatable packer attached to the lower end of said cylinder; a hydraulic motorand a pump in coupled relation supported within said cylinder; a four-way valve including a valve body and a rotatably movable part supported within said cylinder above said motor and said pump; said valve body separating said string of drill pipe from the interior of said cylinder; the intakes of said pump and said motor each extending through and terminating exteriorly of said cylinder; said valve having a shut-position and three sequential port positions; the three port positions being designated by a first port, a second port, and a third port, respectively; a passageway in said movable part communicating at one end with the interior of said pipe string; the opposite end of the passageway being blocked by said valve body in said shut-position and registering sequentially with said first, second, and third ports in the remaining three valve positions; a first conduit connecting the discharge of said motor with said first port; a sample conduit penetrating the wall of said packer; a second conduit piercing said closure and connecting said second port with the sampling conduit within said packer; a third conduit piercing said closure and connecting said third port with the interior of said packer; an additional port in said valve body; a fourth conduit connecting the exhaust of said motor with said additional port; a by-pass within said movable part connecting said additional port and said third port when said passageway is in registry with said first port, said movable part being operable from within said well pipe.

3. In a Well formation tester including an inflatable elastic packer mounted at the lower end of a string of well pipe, the improvement which comprises a fourposition valve having an off-position and three sequential port-positions; said valve separating the interior of the well pipe above the valve from the interior of the packer; first, second, and third ports in the body of said valve corresponding respectively to said three port-positions; the movable part of said valve operable from Within the well pipe and having a passageway communicating at one end with the interior of said well pipe, the opposite end of said passageway being blocked by the body of said valve in said ofi-position and registering sequentially with said first, second, and third ports in the three following port-positions of the valve; a hydraulic motor and a pump in coupled relation supported by said well pipe; a first conduit interconnecting the exhaust of said motor with said first valve port, the intake of said pump and the intake of said hydraulic motor terminating exteriorly of said well pipe and said tester, a second conduit extending from the exterior of said packer through the wall of said packer to said second port, a third conduit interconnecting the interior of said packer with said third valve port, an additional port in said valve body, a fourth conduit interconnecting said additional port with the exhaust of said pump, and a by-pass passageway in said movable part adapted to interconnect said additional port and said third port when said central passageway is in registry with said first port.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. IN A WELL FORMATION TESTER INCLUDING AN INFLATABLE ELASTIC PACKER AND A SAMPLE CONDUIT EXTENDING THROUGH THE WALL THEREOF, THE IMPROVEMENT WHICH COMPRISES A CYLINDER ATTACHABLE AT ITS UPPER END TO THE LOWER END OF A STRING OF WELL PIPE AND AT ITS LOWER END TO SAID PACKER, A HYDRAULIC MOTOR AND A PUMP IN COUPLED RELATION MOUNTED WITHIN SAID CYLINDER, A FOUR-POSITION VALVE MOUNTED WITHIN SAID CYLINDER ABOVE SAID MOTOR AND PUMP AND SEPARATING THE INTERIOR OF THE WELL PIPE FROM THE INTERIOR OF THE PACKER, SAID VALVE HAVING A SHUT-POSITION AND THREE SEQUENTIAL PORT POSITIONS, THE MOVABLE PART OF THE VALVE BEING ROTATABLE WITHIN THE VALVE BODY AND HAVING A PASSAGEWAY COMMUNICATION AT ONE END WITH THE INTERIOR OF THE WELL PIPE, THREE SEPARATE PORTS IN THE BODY OF SAID VALVE, THE OPPOSITE END OF SAID PASSAGEWAY BEING BLOCKED BY SAID VALVE BODY IN A FIRST SAID SHUT-POSITION AND REGISTERING SEQUENTIALLY WITH A FIRST, SECOND, AND THIRD OF SAID THREE PORTS IN THE FOLLOWING THREE PORT-POSITIONS, THE INTAKES OF SAID MOTOR AND SAID PUMP EXTENDING EXTERIORLY OF SAID CYLINDER, A FIRST CONDUIT CONNECTING THE EXHAUST OF SAID MOTOR WITH SAID FIRST PORT, A SECOND CONDUIT CONNECTING SAID SECOND PORT WITH THE END OF SAID SAMPLE CONDUIT WITHIN SAID PACKER, A THIRD CONDUIT CONNECTING SAID THIRD PORT AND THE INTERIOR OF SAID PACKER, AN ADDITIONAL PORT IN SAID VALVE, A FOURTH CONDUIT CONNECTING SAID ADDITIONAL PORT AND THE EXHAUST OF SAID PUMP, AND A BY-PASS PASSAGEWAY WITHIN SAID MOVABLE PART OPERABLE TO COMMUNICATE BETWEEN SAID ADDITIONAL PORT AND SAID THIRD PORT WHEN THE VALVE IS IN ITS FIRST PORT POSITION.

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